Definition of Multi Client-Server and Cygwin - Case Study Example

of the of the Part A Multi Client Socket A socket is defined as the end-point with which network communication takes place. It can be termed as the virtual device that is used by clients and servers to communicate with each other. There are several types of communication possible between servers and clients and the most common type is of multiple clients sending their requests to a server(s). A simple real life example of such communication can be an ftp server where multimedia files are uploaded. Different clients will be sending their requests to the data server to retrieve their required data (“Multi-client Server Design Pattern using Simple TCP/IP Messaging”). Figure 1 shows the network diagram of such communication; Figure 1: Network Diagram for Client and Server communication 2. Example of multi client server Internet Service Provider (ISP) Server for a certain region will listen to a number of internet users. The client will request for connection and connection request will be catered by the server on a queue mechanism so that there are no clients left without service. Another mechanism to handle requests that is very common among multi client servers is based on priority of messages. The server can listen to n number of clients and clients can disconnect from the server at any point of time. There are generally two approaches to handle multi client server implementation. One approach is to have singleton servers for each client i.e. a server instance is created every time a request is received for a connection. This approach is not very practical for real-time systems. The other approach is to designate one server as the ‘connection manager’ that will be catering to a number of clients by retrieving their individual information on need basis. 3. TCP/IP Model The TCP/IP model, also termed as Internet Protocol Suite, defines the format and implementation of a set of networking protocols to facilitate communication between nodes in a network. It is the set of protocols that is used for Internet and other networks. This model is based on protocols and it does not distinguish between service and protocols. TCP/IP model is known to have 4 layers and slightly different names have been given to the respective layers by different researchers. The names that have been chosen by Tanenbaum are: Application: interface to user Transport: end-systems communication Network: routing of packets Host-to-network: connects host to the network 4. TCP/IP Comparison with OSI layers TCP/IP model is usually compared with the OSI Reference model. The following are some of the differences between these two models (Samiullah, “Difference between OSI model and TCP/IP model”); OSI Reference Model TCP/IP Model There are 7 layers. There are 4 layers. It is a reference model It is an implementation of the OSI model. This model is applicable to all systems and networks. This model is limited to certain types of network and protocols. Can only be used as a guidance tool. It is considered to be more credible since the internet is build around this set of protocols. 5. Conclusion   Multi client server gives service to n number of client. Communication takes place over TCP/IP and messages are passed on from the layers of the TCP/IP model to the end-host. OSI reference model can be considered as a guidance tool whereas the TCP/IP model can be used for implementation. Part B 1. Cygwin Cygwin provides the Microsoft Windows users with a Linux-like platform. Cygwin is an environment that gives the features and outlook of Linux. It is used by users that do not have Linux operating system but have to run some application or software with Linux requirements. It consists of two parts; Cygwin1.dll- that provides the Linux platform to perform Linux functionality in the existing operating system. Set of tools that provide the outlook and feel of Linux. (“Cygwin Home”) Cygwin offers the open source standard Red Hat GNU gcc compiler and gdb debugger for Windows users (“Cygwin”). It is based on a compatibility library that installs a Unix API on the Windows operating system (“Windows Unix compatibility”). 2. Installation Requirements The latest version of Cygwin (Cygwin 1.7) is not officially supported by all Windows operating systems, the following list of Windows operating system do not support Cygwin; Windows 95 Windows 98 Windows Me However, the rest of the newer versions of Windows like Windows 2000, Windows XP etc are equipped with the requirements to install Cygwin. 3. Installation Process Download the setup of Cygwin and extract it in the ‘C:’ drive. The drive should have a minimum free space of 2.55 GB. Run the ‘setup.exe’ from the extracted installation package, select “Install from Local Directory” and select “c:\cygwin”. In the “Local Package Directory” select the folder “ftp%3a%2f%...”. The next screen will display a number of packages that will determine what kind of work is required from Cygwin. The required packages for C programming should be selected from each category of packages. The “Devel” category is very important for developers and it should be ensured that ‘gcc’, ‘g++’, ‘gdb’, ‘make’ is selected (“Cygwin Install Notes”). 4. Advantages Cygwin gives the user an opportunity to operate Linux-like environment and get used to it. The user can use it as a test-run of the operating system and can judge if they want to shift to that operating system (“Where to Get a Unix Emulator”). This platform becomes very useful for developers if they want to run open source software under the Windows operating system (“Where to Get a Unix Emulator”). It is a better option as compared to other tools like VMWares. Cygwin is able to perform most of the Linux/Unix functionality under Windows. It minimizes the hassle of switching from one operating system to the other and can increase the pace of work (“PygrOnWindows”). 5. Disadvantages Cygwin applications only run under itself and fail to run when they are called from outside the platform of Cygwin (“Windows Unix compatibility”). The installation of Cygwin might prove to be a tedious task if the exact required packages are not known to the user. Requires a significant amount of free space to be installed on a machine. The speed of compiling and launching programs is slower with Cygwin as compared to Linux. 6. Conclusion Cygwin is a very useful tool to run applications on Windows that actually require Linux operating system. It gives an opportunity to the user to get the functionality of both the operating systems while logging in on only Windows. Works Cited “Cygwin Home”, Cygwin, n.d. Web. 28th July 2010, www.cygwin.com/ “Cygwin”, redHat, 2010, Web. 28th July 2010, http://www.redhat.com/services/custom/cygwin/ “Cygwin Install Notes”, University of Northern Iowa- Computer Science Notes, 26th Aug 2006, Web. 28th July 2010, http://www.cs.uni.edu/~okane/cygwin/install-notes.html “Where to Get a Unix Emulator”, TopBits.com, n.d. Web. 28th July 2010, http://www.tech-faq.com/where-to-get-a-unix-emulator.html “PygrOnWindows”, PYGR, 10th September 2009, Web. 28th July 2010, http://code.google.com/p/pygr/wiki/PygrOnWindows “Windows Unix compatibility”, RUTGERS- State University of New Jersey, 11th October 2009, Web. 28th July 2010, http://techdir.rutgers.edu/winunix.html “A Multi-client Server Design Pattern using Simple TCP/IP Messaging”, National Instruments, n.d. Web. 29th July 2010, ftp://ftp.ni.com/pub/devzone/pdf/tut_3055.pdf Tanenbaum, Andrew. Computer Networks, Prentice Hall, 2002, ISBN 0-13-066102-3, Print Samiullah, Difference between OSI model and TCP/IP model. Data Communication Report, 2009, http://www.scribd.com/doc/14206202/Difference-Between-OSI-and-TCPIP-Models Read More